Positive electrode active material for lithium secondary battery

Abstract

Provided is a novel positive electrode active material which can effectively suppress the quantity of gas generated by the reaction with an electrolytic solution. Proposed is a positive electrode active material for a lithium secondary battery including positive electrode active material particles obtained by equipping the entire surface or a part of a surface of lithium manganese-containing composite oxide particles (also referred to as the “core particles”) operating at a charging voltage in a region exceeding 4.3 V in a metal Li reference potential with a layer A containing at least titanium (Ti), aluminum (Al), zirconium (Zr), or two or more kinds of these.

The invention claimed is: 
     
       1. A positive electrode active material for a lithium secondary battery comprising positive electrode active material particles, wherein the positive electrode active material particles comprises a layer (referred to as the “layer A”) comprising at least titanium (Ti), aluminum (Al), zirconium (Zr), or two or more kinds of these on a part of a surface of lithium manganese-containing composite oxide particles (also referred to as the “core particles”) operating at a charging voltage in a region exceeding 4.3 V in a metal Li reference potential, wherein a content of carbon (C) in the positive electrode active material is less than 0.1% by mass. 
     
     
       2. The positive electrode active material for a lithium secondary battery according to  claim 1 , wherein the layer A further comprises phosphorus (P). 
     
     
       3. The positive electrode active material for a lithium secondary battery according to  claim 1 , wherein a thickness of the layer A is from 0.1 to 200 nm. 
     
     
       4. The positive electrode active material for a lithium secondary battery according to  claim 1 , wherein the positive electrode active material has a specific surface area of from 0.01 to 3.00 m 2 /g. 
     
     
       5. The positive electrode active material for a lithium secondary battery according to  claim 1 , wherein D50 according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is from 3 to 40 μm. 
     
     
       6. The positive electrode active material for a lithium secondary battery according to  claim 1 , wherein D10 according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is from 1 to 20 μm. 
     
     
       7. The positive electrode active material for a lithium secondary battery according to  claim 1 , wherein Dmin according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is 10 μm or less. 
     
     
       8. The positive electrode active material for a lithium secondary battery according to  claim 1 , wherein the lithium manganese-containing composite oxide particles are spinel-type lithium manganese-containing composite oxide particles having an operating potential of 4.5 V or more at a metal Li reference potential. 
     
     
       9. The positive electrode active material for a lithium secondary battery according to  claim 1 , wherein the lithium manganese-containing composite oxide particles are spinel-type lithium manganese-containing composite oxide particles including a crystal phase obtained by substituting a part of Mn sites in LiMn 2 O 4-δ  with Li, a metal element M1, and another metal element M2. 
     
     
       10. A lithium secondary battery comprising the positive electrode active material for a lithium secondary battery according to  claim 1 . 
     
     
       11. A positive electrode active material for a lithium secondary battery comprising positive electrode active material particles, wherein the positive electrode active material particles comprises a layer (referred to as the “layer A”) comprising at least titanium (Ti), aluminum (Al), or both of these on a part of a surface of lithium manganese-containing composite oxide particles (also referred to as the “core particles”) operating at a charging voltage in a region exceeding 4.3 V in a metal Li reference potential, wherein a content of carbon (C) in the positive electrode active material is less than 0.1% by mass. 
     
     
       12. The positive electrode active material for a lithium secondary battery according to  claim 11 , wherein the layer A further comprises phosphorus (P). 
     
     
       13. The positive electrode active material for a lithium secondary battery according to  claim 11 , wherein a thickness of the layer A is from 0.1 to 200 nm. 
     
     
       14. The positive electrode active material for a lithium secondary battery according to  claim 11 , wherein the positive electrode active material has a specific surface area of from 0.01 to 3.00 m 2 /g. 
     
     
       15. The positive electrode active material for a lithium secondary battery according to  claim 11 , wherein D50 according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is from 3 to 40 μm. 
     
     
       16. The positive electrode active material for a lithium secondary battery according to  claim 11 , wherein D10 according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is from 1 to 20 μm. 
     
     
       17. The positive electrode active material for a lithium secondary battery according to  claim 11 , wherein Dmin according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is 10 μm or less. 
     
     
       18. The positive electrode active material for a lithium secondary battery according to  claim 11 , wherein the lithium manganese-containing composite oxide particles are spinel-type lithium manganese-containing composite oxide particles having an operating potential of 4.5 V or more at a metal Li reference potential.